Non-contact thermophysical property measurements of refractory metals using an electrostatic levitator

The electrostatic levitation system, including its history and development, and techniques for non-contact thermophysical property measurements (density, surface tension, and viscosity) are reviewed. Thermophysical properties of refractory metals whose melting temperatures are over 2,000 K have been measured with an electrostatic levitator. The experimental results for vanadium, zirconium, niobium, molybdenum, rhodium, ruthenium, iridium, tantalum, rhenium, tungsten, and rhenium are presented. Comparison between theoretical calculations based on hard sphere model and measured data, as well as the necessity of microgravity conditions for this research are also discussed.